Computers are now typically backed up on a regular basis. There can be many situations where it may be desirable to recover a specific file or a set of files that is less than the entire directory. A situation may also arise where it may be desirable to recover something that is less than the whole of what is stored in the backup storage medium. In such cases, an index identifying the contents of a particular storage medium can be used to assist in the recovery of a portion of what has been backed up.
A problem with the use of such indexes is the time that it can take to process and create the index. As the amount of backed up information becomes larger, the time it takes to create and process an associated index can grow exponentially. It would be desirable to have a more efficient technique for indexing the backed up information.